In this article we will be covering SSH port forwarding also known as SSH tunneling.

As previously discussed in our previous article Proxing Web Traffic across a SSH Tunnel using SSH Dynamic Port Forwarding, SSH port forwarding (or tunneling) re-routes TCP/IP connections through an established SSH connection. Being encapsulated within SSH provides security benefits along with the ability to route traffic through firewalls using just port 22 (SSH).

Note : This article includes - Putty Commands (Windows) / SSH Commands (Linux)  

Forwarding your local port to a remote address

This allows you to forward you local port to a remote address.

Our example is based on a VNC connection to your server over a secure connection.This will create a port of 7777 on your local host. All traffic to this port will be forwarded to your remote server IP (over ssh) to the port of 5900.

C:\Documents and Settings\admin> putty -L 7777:[Local Server IP]:5900 [Remote Server IP]

[root@linux]# ssh  -L 7777:[Local Server IP]:5900 [Remote Server IP]

Forwarding a remote port to your local address

This allows you to forward a remote port to your localhost.

Our example below is based on a RDP into a workstation that is sitting behind a firewall of which you only have a outbound ssh access from. 
Below will create a port of 7777 on your remote host. All traffic to this port will be forwarded to your local workstation (over ssh) to the port of 3389.

C:\Documents and Settings\admin> putty -R 7777:127.0.0.1:3389 [remote server ip]

[root@linux]# ssh -R 7777:127.0.0.1:3389 [remote server ip]